<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>index</title>
</head>
<body>
    <div>
        <input type="checkbox" name="aa" value="0" />0
        <input type="checkbox" name=" aa " value="1" />1
        <input type="checkbox" name=" aa " value="2" />2
        <input type="checkbox" name=" aa " value="3" />3
        <input type="button" onclick="abc()" value="提 交" />
        <div id="allselect"></div>

        <div>
            <form name="a">
                <select name="a" size="1" onchange="_sel(this)">
                <option value="a">1</option>
                <option value="b">2</option>
                <option value="c">3</option>
                </select>
            </form>
        </div>

        <div>
            用户名：<input type="text" id="username"/><br/>
            密  码：<input type="password" id="password"/><br/>
        　　 确认密码：<input type="password" id="password1"/><br/>
            <button id="btnSubmit" type="button">提交</button><br/>
        </div>

        <table>
            <tr>
                <td>留言</td>
                <td id="number"> 0 </td>
            </tr>
            <tr>
                <td colspan=2>
                    <textarea id="feedBack" onkeyup="test()" rows=6></textarea>
                </td>
            </tr>
        </table>


    </div>
    <script src="./jquery-3.6.0.js"></script>
    <script src="./base.js"></script>
</body>
</html>